Examine source code of XPath Ultra

{
  "manifest_version": 2,
  "name": "XPath Ultra",
  "version": "2.2.0",
  "description": "Extract, edit, and evaluate XPath queries on any webpage",
  "author": "Uve",
  "browser_specific_settings": {
    "gecko": {
      "id": "{a0fa0bf0-d6a2-43ee-80f0-49bb9d0f30d3}",
      "data_collection_permissions": {
        "required": [
          "websiteContent"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_start"
    }
  ],
  "commands": {
    "toggle-xpath-helper": {
      "suggested_key": {
        "default": "Ctrl+Shift+X"
      },
      "description": "Toggle XPath Helper"
    }
  },
  "web_accessible_resources": [
    "bar.html",
    "bar.css",
    "bar.js"
  ],
  "icons": {
    "48": "icons/icon-48.svg",
    "96": "icons/icon-96.svg"
  },
  "browser_action": {
    "default_icon": {
      "48": "icons/icon-48.svg"
    },
    "default_title": "XPath Ultra"
  }
}